Your timing light may be used on vehicles with 6-volt electrical systems by using the following connection procedure: 12-volt automotive battery required.1. Connect the RED battery clip to the positive (+) terminal of a 12-volt battery.2. Connect the BLACK battery clip to the negative (-) terminal of a 12-volt battery.3. Using a length of 18AWG jumper wire, ground the negative (-) terminal of the 12-volt battery to a known-good ground on the vehicle under test.

Make sure the battery clips are firmly connected to the battery terminals. Make sure the battery clip polarity is correct (red battery clip is connected to the positive (+) battery terminal, black battery clip is connected to the negative (–) battery terminal).